# Accession Number:

## ADA209260

# Title:

## Prediction of Time-to-Go for a Homing Missile Using Bang-Bang Control

# Descriptive Note:

## Technical paper Aug 1987-Sep 1988

# Corporate Author:

## TEXAS UNIV AT AUSTIN DEPT OF AEROSPACE ENGINEERING AND ENGINEERING MECHANICS

# Personal Author(s):

# Report Date:

## 1989-04-01

# Pagination or Media Count:

## 7.0

# Abstract:

The flight time required for a variable-speed homing missile to intercept a zero-acceleration target in two dimensions is determined by assuming that the missile normal acceleration is bang-bang, that is, maximum normal acceleration followed by zero normal acceleration where the switch time which gives intercept is to be determined. For those cases where intercept does not occur in a reasonable time, the flight time which minimizes the miss distance is used. A tangential acceleration profile is assumed for the missile, so that the velocity of the missile becomes a known function of time, and the equations of motion can be solved analytically. Then, an algebraic equation for the switch time for intercept or the final time for closest approach can be derived, but it must be solved numerically. Results show that this time-to-go algorithm improves the performance miss distance of the missile for several scenarios relative to the range-over-closing-speed algorithm.

# Descriptors:

- *GUIDED MISSILE TRAJECTORIES
- *INTERCEPT TRAJECTORIES
- *HOMING
- CONTROL
- OPTIMIZATION
- EQUATIONS OF MOTION
- PREDICTIONS
- ACCELERATION
- ALGEBRA
- PROFILES
- FLIGHT
- TANGENTS
- NUMERICAL METHODS AND PROCEDURES
- EQUATIONS
- PULSE MODULATION
- SWITCHES
- MISS DISTANCE
- TIMING DEVICES
- GUIDED MISSILES
- VARIABLE SPEED DRIVES
- VELOCITY
- ALGORITHMS

# Subject Categories:

- Numerical Mathematics
- Guided Missile Trajectories, Accuracy and Ballistics